[FFmpeg-devel] [PATCH 2/2] RFC: checkasm: motion: Test different h parameters

[Martin Storsjö]

Previously, the checkasm test always passed h=8, so no other cases
were tested.

Out of the me_cmp functions, in practice, some functions are hardcoded
to always assume a 8x8 block (ignoring the h parameter), while others
do use the parameter. For those with hardcoded height, both the
reference C function and the assembly implementations ignore the
parameter similarly.

The documentation for the functions indicate that heights between
w/2 and 2*w, within the range of 4 to 16, should be supported. This
patch just tests random heights in that range, without knowing what
width the current function actually uses.
---
I'm not sure if it's good to have checkasm exercise cases that
don't occur in practice or not. In particular, the aarch64
functions have a separate implementation for non-multiple-of-4
height, which probably doesn't ever get called in practice, while
other SIMD implementations lack that.

Alternatively, we'd improve the documentation for the expectations
for these functions and make the test match that, and remove the
unused non-multiple-of-4 case in the aarch64 assembly.
---
 tests/checkasm/motion.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/tests/checkasm/motion.c b/tests/checkasm/motion.c
index 0112822174..79e4358941 100644
--- a/tests/checkasm/motion.c
+++ b/tests/checkasm/motion.c
@@ -45,7 +45,7 @@ static void test_motion(const char *name, me_cmp_func test_func)
     /* motion estimation can look up to 17 bytes ahead */
     static const int look_ahead = 17;
 
-    int i, x, y, d1, d2;
+    int i, x, y, h, d1, d2;
     uint8_t *ptr;
 
     LOCAL_ALIGNED_16(uint8_t, img1, [WIDTH * HEIGHT]);
@@ -68,14 +68,16 @@ static void test_motion(const char *name, me_cmp_func test_func)
         for (i = 0; i < ITERATIONS; i++) {
             x = rnd() % (WIDTH - look_ahead);
             y = rnd() % (HEIGHT - look_ahead);
+            // Pick a random h between 4 and 16; pick an even value.
+            h = 4 + ((rnd() % (16 + 1 - 4)) & ~1);
 
             ptr = img2 + y * WIDTH + x;
-            d2 = call_ref(NULL, img1, ptr, WIDTH, 8);
-            d1 = call_new(NULL, img1, ptr, WIDTH, 8);
+            d2 = call_ref(NULL, img1, ptr, WIDTH, h);
+            d1 = call_new(NULL, img1, ptr, WIDTH, h);
 
             if (d1 != d2) {
                 fail();
-                printf("func: %s, x=%d y=%d, error: asm=%d c=%d\n", name, x, y, d1, d2);
+                printf("func: %s, x=%d y=%d h=%d, error: asm=%d c=%d\n", name, x, y, h, d1, d2);
                 break;
             }
         }
-- 
2.25.1